Thallium borates

The only recent authoratitive work on hydrated thallium borates is that by Touboul, who reviewed the field in 1971 (412). It is clear that insufficient data are available to rationalize the thallium borates, but there is definite evidence for the compounds 1 2 1, 1 2 3, 1 2 6, 1 5 8, 3 1 x, and 2 5 5, which is stable up to 100°C. 

Historically, almost every chemical or compound known to be toxic has been tried and used to inhibit the action of wood-destroying pests. Among the many chemicals used as wood preservatives are compounds based on creosote, mercury, arsenic, thallium, borate, cyanide, chromium, copper, zinc, nickel, fluorides, and pentachlorophenol. The majority fall into 3 classes ... 

Chemistry, syntheses, and applications of thallium(I) hydrotris(pyrazolyl)borate [TpTl(I)] 98MI44. 

Thallium tris(3-mesitylpyrazol-l-yl)borate and [(j -cod)2RhCl] produce [(ry -TpORhfjj -cod)] (93IC3471). These complexes appeared to be good catalysts... 

All of these compounds 151a (Figure 16) have been made from the lithium salt of anionic tridentate phosphino-borate 152 or more conveniently from the thallium(l) derivative 153, available from 152 and T1PF6 in water-methanol media (Scheme 60) <1999CC2379, 1999JA9871, 2001CC2152, 2003IC5074>. 

The thallium salts 153 are stable to moisture and oxygen both in solution and in the solid state. X-ray crystallography of 153a (R = Ph) revealed a significant separation between the thallium ion and the anionic borate counteranion (B-Tl distance is equal to 425.3 pm) <2001CC2152>. 

BP3TIC45H41, Thallium, phenyltris(diphenyl-phosphinomethyl)borate, 34 12... 

P3BTIC45H41, Thallium, phenyltris(diphenyl-phosphinomethyl)borate, 34 12 P4Br2MoO4C36H30, Molybdenum(Vl), bis(tri-phenylphosphineoxide)dibromodioxo-, 34 53... 

The lack of data on certain metal borate systems has been implied in Section V. Quite apart from thallium, zinc, and lead compounds, the range of known borates of barium and strontium is somewhat limited. There are no obvious reasons why the latter should not have stability ranges approaching those of calcium and magnesium borates. Clearly, more investigations are necessary in this area. 

---